It is known that certain quinoline compounds exhibit antibacterial properties, notably certain 7-piperazinyl-4-oxo-1,4-dihydroquinoline-3-carboxylic acids. In U.S. Pat. No. 4,017,622, there are disclosed certain 7-piperazinyl-4-oxo-1,4-dihydroquinoline-3-carboxylic acids derivatives which are substituted in the 1 position with an alkyl, benzyl or acetyl substituent. U.S. Pat. No. 4,292,317 discloses derivatives of 7-piperazinyl-4-oxo-1,4-dihydroquinoline-3-carboxylic acids wherein the 1 position is substituted by an alkyl group or a vinyl group. In U.S. Pat. No. 4,284,629, there are disclosed various 4-oxo-1,4-dihydroquinoline-3-carboxylic acids in which the 1 position is substituted with a cycloalkyl group.
It is also known that certain naphthyridine compounds exhibit antibacterial properties, notably certain 7-piperazinyl-4-oxo-1,8-naphthyridine-3-carboxylic acids. In European Patent No. 9,425, there are disclosed certain 7-piperazinyl-6-fluoro-1,4-dihyro-4-oxo-1,8-naphthyridine-3-carboxylic acids derivatives which are substituted in the 1 position with an alkyl or vinyl substituent. U.S. Pat. No. 4,616,019 discloses derivatives of 7-substituted-amino-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acids derivatives which are substituted in the 1 position with an aromatic group such as substituted phenyl.